Statue of Fibonacci.
Leonardo Pisano Bogollo, (c. 1170 – c.
1250) also
known as Leonardo of Pisa, Leonardo
Pisano, Leonardo Bonacci,
Leonardo Fibonacci, or, most commonly, simply
Fibonacci, was an Italian mathematician, considered by some "the most
talented mathematician of the Middle
Ages".
Fibonacci is best known to the modern world for:
Biography
Leonardo Bonacci was born around 1170AD to Guglielmo Bonacci, a
wealthy Italian merchant.
Guglielmo directed a trading post (by some
accounts he was the consultant for Pisa) in Bugia, a port east of Algiers in the Almohad dynasty's sultanate in North Africa (now Bejaia, Algeria). As
a young boy, Leonardo traveled with him to help; it was there he
learned about the HinduArabic numeral system.
Recognizing that arithmetic with HinduArabic numerals is simpler
and more efficient than with
Roman
numerals, Fibonacci traveled throughout the Mediterranean world
to study under the leading Arab mathematicians of the time.
Leonardo returned from his travels around 1200. In 1202, at age 32,
he published what he had learned in
Liber Abaci (
Book of Abacus or
Book of Calculation), and thereby introduced HinduArabic
numerals to Europe.
Leonardo became an amicable guest of the Emperor
Frederick II, who enjoyed
mathematics and science. In 1240 the Republic of Pisa honored
Leonardo, referred to as Leonardo Bigollo,See the incipit of
Flos: "Incipit flos Leonardi
bigolli pisani..." (quoted in the
MS Word document
Sources in Recreational Mathematics: An Annotated
Bibliography by David Singmaster, 18 March 2004  emphasis
added), in English: "Here starts 'the flower' by Leonardo the
wanderer of Pisa..."
The basic meanings of "bigollo" appear to be "goodfornothing" and
"traveler" (so it could be translated by "vagrant", "vagabond" or
"tramp"). A. F. Horadam contends a connotation of "bigollo" is
"absentminded" (see first footnote of
"Eight hundred years young"), which is also one of the
connotations of the English word "wandering". The translation "the
wanderer" in the quote above tries to combine the various
connotations of the word "bigollo" in a single English word. by
granting him a salary.
In the 19th century, a statue of Fibonacci was constructed and
erected in Pisa.
Today it is located in the western gallery of
the Camposanto, historical cemetery on the Piazza dei
Miracoli.
Liber Abaci
In the
Liber Abaci (1202), Fibonacci introduces the
socalled
modus Indorum (method of the Indians), today
known as Arabic numerals (Sigler 2003; Grimm 1973). The book
advocated numeration with the digits 0–9 and
place value. The book showed the practical
importance of the new
numeral system,
using
lattice multiplication
and
Egyptian fractions, by
applying it to commercial
bookkeeping,
conversion of weights and measures, the calculation of interest,
moneychanging, and other applications. The book was well received
throughout educated Europe and had a profound impact on European
thought.
Liber Abaci also posed, and solved, a problem involving
the growth of a hypothetical population of rabbits based on
idealized assumptions. The solution, generation by generation, was
a sequence of numbers later known as
Fibonacci numbers. The number sequence was
known to Indian mathematicians as early as the 6th century, but it
was Fibonacci's
Liber Abaci that introduced it to the
West.
Fibonacci sequence
In the Fibonacci sequence of numbers, each number is the sum of the
previous two numbers, starting with 0 and 1. Thus the sequence
begins0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610
etc.
The higher up in the sequence, the closer two consecutive "
Fibonacci numbers" of the sequence divided
by each other will approach the
golden
ratio (approximately 1 : 1.618 or
0.618 : 1).
The golden ratio was used widely in the Renaissance in
paintings.
In popular culture
Books written by Fibonacci
See also
Notes
 http://library.thinkquest.org/27890/biographies1.html
 Howard Eves.
An Introduction to the History of Mathematics. Brooks
Cole, 1990: ISBN 0030295580 (6th ed.), p 261.
 Leonardo Pisano  page 3: "Contributions to number
theory". Encyclopædia Britannica Online,
2006. Accessed 18 September 2006.
 Parmanand Singh. "Acharya Hemachandra and the (so called)
Fibonacci Numbers". Math. Ed. Siwan , 20(1):2830, 1986.
ISSN 00476269]

http://www.maths.surrey.ac.uk/hostedsites/R.Knott/Fibonacci/fibBio.html
 Fibonacci's Statue in Pisa
References
 Goetzmann, William N. and Rouwenhorst, K.Geert, The Origins
of Value: The Financial Innovations That Created Modern Capital
Markets (2005, Oxford University Press Inc, USA), ISBN
0195175719.
 Grimm, R. E., "The Autobiography of Leonardo Pisano", Fibonacci
Quarterly, Vol. 11, No. 1, February 1973, pp. 99104.
 A. F. Horadam, "Eight hundred years young," The Australian
Mathematics Teacher 31 (1975) 123134.
External links
 [http://library.thinkquest.org/27890/biographies1.html.
Fibonacci Biography
 Who was Fibonacci? by Ron Knott.
 Goetzmann, William N., Fibonacci and the
Financial Revolution (October 23, 2003), Yale School of
Management International Center for Finance Working Paper
No. 0328 [2605]
 Charles Burnett, Leonard of Pisa (Fibonacci) and Arabic
Arithmetic  the Medieval background to Fibonacci's work
 Fibonacci at Convergence
 wallstreetcosmos.com, Fibonacci numbers and stock market analysis,
(2008).
 O'Connor, John J and Robertson, Edmund F. "Leonardo Pisano Fibonacci – 1170  1250" in
The MacTutor History of Mathematics archive.
University of St
Andrews website, Scotland, 1998.
 Liber
Abaci and its Egyptian fraction methods